Transit systems typically operate with defined routes including planned stopping points where transit system users can board transit vehicles. The layout of these stopping points is designed to correlate to a schedule that allows a transit vehicle to travel and arrive at specific stopping points at specific stopping times. Transit system users depend on schedules of these specific stops and stopping times to plan trips using the transit system.
Often transit vehicles vary from schedules because of traffic density variations, ridership variations, route variations, weather variations, and other issues that can cause a transit vehicle to run ahead or behind schedule. When a transit vehicle varies from a planned schedule a transit system user may not have knowledge of the variations, and may lose confidence in the transit system because of the frustrations involved with the unpredictable nature of the transit system's schedule. If a user becomes frustrated with a transit system, the user may choose alternate forms of transit.